Submission #203344

#	Time	Username	Problem	Language	Result	Execution time	Memory
203344		Fasho	Hacker (BOI15_hac)	C++14	0 / 100	5 ms	384 KiB

hac

#include <bits/stdc++.h>
#define N 1000005
#define ll long long int 	
#define MP make_pair
#define pb push_back
#define ppb pop_back
#define sp " "
#define endl "\n"
#define fi first
#define se second
#define ii pair<int,int>
#define lli pair<ll,ll>
#define fast cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(false)
#define fast2 freopen ("badhair.gir","r",stdin);freopen ("badhair.cik","w",stdout);
#define mod 1000000007
#define fs(x,y) for(ll i=1;i<=y;i++) cin>>x[i]
#define fo(i,x,y) for(ll i=x;i<=y;i++)
#define INF 1000000000005
#define ull unsigned long long int
using namespace std;

ll n,m,ar[N],sum,t,pref[N];

ll calc1(int ind,int len)
{
	ll top=0;
	if(ind-len<1)
	{
		top+=pref[ind-1];
		ll x=1-(ind-len);
		top+=pref[n]-pref[n-x];
		return top;
	}
	return pref[ind-1]-pref[ind-len-1];
}
ll calc2(int ind,int len)
{
	if(ind+len<=n)
		return pref[ind+len]-pref[ind];
	ll top=0;
	top+=pref[n]-pref[ind];
	ll x=ind+len-n;
	return top+pref[x];


}

int main()
{
	fast;
	cin>>n;
	fs(ar,n);
	pref[0]=0;
	fo(i,1,n)
		pref[i]=pref[i-1]+ar[i];
	m=(n+1)/2;
	m--;
	// cout<<calc1(1,1)<<endl;
	fo(i,1,n)
	{
		ll top=ar[i];
		ll x=calc1(i,m);
		ll y=calc2(i,m);
		// cout<<i<<sp<<x<<sp<<y<<endl;
		top+=min(x,y);
		sum=max(sum,top);
	}
	cout<<sum;

}



/*     cd onedrive\desktop\kod
cls

Sinav:21-22 aralik
Aciklama: Muhtemelen 25 aralik
*/

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 40